Method of recording sound



on 2.110.090 A March 1, 1938. c. G. LIGH n AL 2,110,090

METHOD OF RECORDING SOUND Filed Dec 28, 1935 y TWO STAGE THREE STAGE PRE-AMP. MAIN AMP AUDIO POWER 7 OSCILLATOR SUPPLY M VACUUM TUBE CIRCUIT DJ Patented Mar. 1, 193a 2 110 0 0 UNITED STATES PATENT OFFICE METHOD OF RECORDING SOUND Charles G. Ligh, New Dorp, Staten Island, and Arthur G. Prevln, New York, N. Y., assignors to Electreporter, Inc., a corporation of Delaware Application December 28, 1935, Serial No. 56,556

6 Claims. (Cl. 274-46) This invention relates to the recording of proholds true of additional possible participants, ceedings in courts or other assemblages, by means such as jurymen, and so forth. As is wellof electric recording devices where the spoken known, the typewritten transcript of such atrial, words are imposed upon a recording medium. in order to be intelligible, must contain not only 5 This recording medium may be a disc, 2. cylinder, the words spoken by each participant, but also (of suitable material or coating),wire, film, paper, his name, Mr. Jones, Mr. Smith, etc., or a or other material capable of receiving and redesignation, such as The Court, Plaintiff's taining the recording. The recording may be counsel", The witness, Juror No. 6, etc. accomplished by means of electrical pickup by or This invention provides a positive yet simple 10 through one or more microphones and electrically method or means whereby such identification is 10 amplified through appropriate circuits to the audibly placed upon the record during recordings necessary strength to record upon the recording of this kind in such manner that it does not erase medium employed for reproduction or so-called or blur anything else upon the record. Its operplayback. ation is practically instantaneous, so that the In such recordings where there are several recorder can apply the identification even to 15 speakers taking part in the proceedings, it is short remarks, rulings or interjections, which desirable that an identification of each speaker however, it may be of greatest importance to have be placed upon the record simultaneously with properly identified. Furthermore, as will be or shortly following each remark which he apparent from the means employed, the operamakes, also that this identification, although tion is practically noiseless. 20 placed upon the record simultaneously with The now-favored way of carrying out the inspeech being recorded thereon, does not erase vention will be understood from the following: or blur any of the speech; that it be audible to It is well known that the normal extreme range one who listens back or transcribes from such of the speaking voice is limited in its cycle range, record; and that each of several speakers has a and that infinite changes in this range are condistinctive and different identification. Thus, a tinuously occurring in any given sounds due to typist transcribing from such record, when he the infinite variations of frequency occasioned has been supplied with the distinctive identificaby the great variety in the vowels and consonants tion signal for each speaker, can readily insert uttered, and their combinations, to form words the name or descriptive designation before each and sentences. We have found in practice that remark made by any one of several speakers, a signal (that is, one or more short or relatively even though the typist was not present at the longer notes or tones, sometimes called dot and hearing, and even though he be unfamiliar with dash) of a constant frequency, and preferably the voices of the various speakers upon the record although not necessarily at a pitch higher than from which he is transcribing. the normal speaking voice, may be simultane- 35 It is furthermore desirable that the means ously imposed upon the recording medium to provided to accomplish the object sought be gether with the speech without erasing, blurring, practically noiseless in operation in the hearing or in anywise interfering with or resulting or record room, ce it s po t that Such in whole or partial extinguishment of either. By

proceedings be not disturbed y distracting using different combinations of such constant 40 mechanisms sounds emanating from their frequency signal in the familiar dot and dash operation. telegraph method, for each of the several voices Illustrative of recording a typical proceedi or speakers upon the record, a positive identificaf t Identlflcation requirements with which tion of each is provided. The identification sigthls Invention concerns itself is an Ordinary nal of constant frequency is distinctly audible at court trial. The usual minimum number of th i e dentical spot in the record that speech constant active participants therein is four,-the

which is of varying frequency) is likewise presiding ustice, plaintifls counsel, defendants dbl Th h both di H u t counsel, and witness upon the stand. Itisessen- 1 e ear .ears 5 no y jus as tial that each such participant have his statethe eye Sees two omens at levels" 50 ments wherever they occur upon the recording To impose the slmult'ianeous 5133a] upon the medium, unmistakably id tifi d as emanating record, we preferably provide an audio oscillaf m ibl similarities of voice qualities tor vacuum tube circuit, electrically connected to make it impractical to rely solely upon the rethe common pow r supply f h recording pp corded voices for the identifications. The same ratus. The oscillator functions only when a 55 key provided for that purpose is depressed, thus closing the oscillator circuit.

Other means than the tube oscillator for gencrating these audio signals may be employed, such as, for instance a buzzer placed in a sound proof box and operated by battery and a key.

The invention will be more clearly understood from the following description of a now preferred embodiment of apparatus to carry out the same as illustrated in the accompanying drawing which is essentially a schematic layout of the apparatus.

Referring to the said drawing in detail, the carrier for the sound record, which is here assumed to be a disc I, with the customary spiral sound groove, is shown to be carried by the rotating table 2. The recording head or cutter is indicated at 3, the sounds being recorded as well understood in the electrical recording art, by the preamplifier 4 and the main amplifier 5, as picked up by the microphone or microphones 6. The power supply for these amplifiers is indicated at I. At 8 is shown an ordinary telegraph key by means of which the circuit can be closed by pressing the same, and thus producing the desired signals upon the record I by the audio oscillator circuit 9 loosely coupled to the amplifiers. The operation of key 8 is practically inaudible to those present, but the signal passing through the oscillator circuit through the amplifier to the recording head or unit, imposes the audible signal upon the record, according to the invention.

A simple illustration of a code for identifying the active participants in a trial as hereinabove referred to would be to have one dot for the presiding justice, two dots for plaintiffs counsel, and dot and dash for defendants counsel, etc.

The recording operator gives to the listening or transcribing typist his dot and dash code with the name of the appropriate speaker against his dot, dash or dot-and-dash combination, and the listener or transcriber is thereby enabled positively and unmistakably to attribute each remark to the proper person when typing the transcript from the record.

We claim:

1. The method of identifying respective state- 5 ments or a plurality of speakers simultaneouslyi with recording of their voices upon a reproduc-' lble sound record, which consists in imposing upon said record by means of an oscillator during the recording, signals of varying duration and 01 constant frequency, each of said signals serving as an identification for a particular speaker.

2. The method defined in claim 1 wherein said signals are of higher pitch than the voices 15 recorded.

3. The methoddefined in claim 1, wherein said signals are of higher than normal speech frequencies.

4. The method of identifying sound originating 20 from a plurality of sources which consists in recording the sounds upon a sound record, and in recording upon said sound record simultaneously therewith, a signal to distinguish one of said sources from another. 25

record a signal to identify each of said sources, W and in reproducing the sound from the record and identifying the plurality of sources by said signals.

CHARLES G. LIGH. ARTHUR G. PREVIN. 

